CS 121

Software Engineering

The scale of modern software systems is truly amazing. We regularly use software that is hundreds-of-thousands to millions of lines of code, and that software, while certainly not bug-free, mostly does what it is supposed to. Achieving this kind of scale has been the result of steady progress in software engineering over the last several decades.

In this class, we will study the foundations of software engineering, focusing on the core principles and ideas that enable us to build large-scale software systems. Our focus will be on the coding side of software engineering. We will explore ideas such as abstraction, modularity, architecture, specification, testing, and debugging, among others. Equally important, but deferred to a different course, is the people/team side of software engineering.

The course will be conducted in Java, and will include a short introduction to Java at the beginning. During the course, students will complete a number of programming assignments, and the course will also include some reading assignments.

Prerequisite: CS 15, graduate standing, or instructor consent.

Syllabus subject to change until the start of the semester


CS 15, graduate standing, or instructor consent.

List of Topics (Tentative)

Below is an approximate list of topics for class. The exact topics will be determined based on the pace of the class.

Office Hours and Web Forum

Office hours for the instructional staff will be posted on the course web page a few days into the semester. You can stop by the office hours for any instructional staff member, no appointment necessary. If you are unable to make office hours and need to speak to a staff member, please contact us to set up an appointment at a different time.

While we will provide assistance with assignments during office hours, you are responsible for developing and debugging your own programs. Do not rely on the instructional staff to make your project work.

Important announcements will be made in class or on the web forum. Please make it a habit to check the web forum daily, and/or sign up to receive email when updates are posted to the web forum. You may also use the class web forum to ask general questions of interest to the class as a whole, e.g., administrative issues or project clarification questions. Please do not post any information that would violate the University's Academic Integrity Policy.


You are responsible for all material discussed in class and posted on the class web page, including announcements, deadlines, policies, etc. Your final course grade will be determined according to the following percentages:

Projects/homework 50%
Readings 10%
Midterm 20%
Final 20%

Any request for reconsideration of any grading on coursework must be submitted within one week of when it is returned. Exam regrading requests must be made in writing. Any coursework submitted for reconsideration may be regraded in its entirety, which could result in a lower score if warranted.

Final course grades will be curved as necessary, based on each student's total numeric score for all coursework at the end of the semester. Important: Completing the programming assignments is an essential part of the course. Therefore, we may fail any student who does not make a good-faith attempt on all course projects, regardless of the student's performance or scores on the other coursework.

Important note: In this class, work allowable for credit is graded at C- or above. Work that is not satisfactory earns a failing grade of F. For this reason, grades of D, D-, and D+ will not be awarded in this class.

Programming Projects

Projects must be submitted electronically following the instructions given in class. Projects may not be submitted by any other means (e.g., please do not email your projects to us). It is your responsibility to test your program and verify that it works properly before submitting. All projects are due at 11:59pm on the day indicated on the project assignment, according to the submission server's internal clock. Your project score will be for the last version of the project you submit. (Reading assignments are due by the start of class on the due date.)

You have two late tokens that you can use during the semester. Using one late token allows you to submit one project up to 24 hours late with no penalty. You may also use your two late tokens together to submit one project up to 48 hours late with no penalty. Contact a TA if you need to check the status of your late tokens. Late tokens may not be used for reading assignments or test cases. Projects submited late without tokens, or with insufficient tokens, will receive a score of zero.

Exam Scheduling

The class includes a midterm and a final exam. Tentative dates for the exams will be posted on the class web site. The exact dates will be confirmed later. We will let you know the exact dates well in advance.

Professional Conduct and Course Environment

You are expected to conduct yourself in a courteous, professional, and collegial manner in all interactions with your fellow students and course staff, both within and outside of the classroom.

This course welcomes all students regardless of age, background, beliefs, race, ethnicity, social class, gender, gender identity, gender expression, national origin, documentation status, religious affiliation, sexual orientation, ability, and any other visible and non-visible differences. If you feel unwelcome for any reason, please let us know so we can work to make things better. Talk to anyone on the teaching staff, or if that feels uncomfortable, try your academic advisor, any other faculty member, the department TA ombudsperson (who can be reached by emailing ta-ombudsperson@cs.tufts.edu), the department chair, or the dean.

Please be aware that the course instructor is a mandated reporter under the university's Sexual Misconduct Policy and Non-Discrimination Policy. If you would like to access confidential counseling for an issue, there are a number of Resources you can access.

Course Meeting Recordings

All course meetings in the class will be recorded. By participating in class, you consent to the recording. If you have objections to being recorded, please let the instructor know before class. Not participating in a recorded class will not affect your grade. The instructor will aim to post all recordings on Canvas, but we cannot guarantee that all classes will be successfully recorded. You may not share course videos outside this course.

Mental Health Support

As a student, there may be times when personal stressors or difficulties interfere with your academic performance or well-being. The Dean of Student Affairs Office offers support and care to undergraduates and graduate students who are experiencing difficulties, and can also aid faculty in their work with students. In addition, through Tufts’ Counseling and Mental Health Service (CMHS) students can access mental health support 24/7, and they can provide information on additional resources. CMHS also provides confidential consultation, brief counseling, and urgent care at no cost for all Tufts undergraduates as well as for graduate students who have paid the student health fee. To make an appointment, call 617-627-3360. Please visit the CMHS website: http://go.tufts.edu/Counseling to learn more about their services and resources.

Academic Support at the StAAR Center

The StAAR Center offers a variety of FREE resources to all students. Students may make an appointment to work on any writing-related project or assignment, attend subject tutoring in a variety of disciplines, or meet with an academic coach to hone skills like time management and navigating procrastination. Students can make an appointment for any of these services by visiting https://students.tufts.edu/staar-center.

Accommodations for Students with Disabilities

Tufts is committed to providing equal access and support to all qualified students through the provision of reasonable accommodations. If you have a disability that requires reasonable accommodations, contact the StAAR Center at StaarCenter@tufts.edu or 617-627-4539. Please be aware that accommodations cannot be enacted retroactively, making timeliness a critical aspect for their provision.

Please also contact the instructor to discuss any necessary accommodations.

Excused Absences

You are expected to attend class regularly, complete course assignments on time, and take exams at the scheduled times. If you are unable to fulfill these requirements due to absence for a good reason, the instructor will excuse the absence and provide accommodation. Events that justify an excused absence include:

It is your responsibility to inform the instructor in advance of intended religious observances. Notice must be provided immediately upon an exam date being announced or confirmed for an absence to be excused.

The policies for excused absences do not apply to project assignments. Projects will be assigned with sufficient time to allow students to carry out the work even with other responsibilities. In cases of extremely serious documented illness of lengthy duration or other protracted, severe emergency situations, the instructor may consider extensions depending on the specific cirucmstances.

Absences stemming from job interviews, traffic or transportation problems, personal travel, and similar will not be excused.

Academic Integrity

The university's Academic Integrity Policy will be strictly enforced.

Unless otherwise specified, programming projects are to be written individually. Therefore, cooperation or use of unauthorized materials on projects is a violation of the Academic Integrity Policy. Project solutions may not be posted online. Any evidence of this, or of unacceptable use of computer accounts, use of unauthorized materials or cooperation on exams or quizzes, or other possible academic integrity violations will be reported.

For learning the course concepts, students are welcome to study together or to receive help from anyone else. You may discuss with others the project requirements, the features of the programming languages used, what was discussed in class and in the class web forum, and general syntax errors. Examples of questions that would be allowed are "Does a Java class definition end in a semicolon?" or "What does a 'class not found' error indicate?", because they convey no information about the contents of a project.

When it comes to actually writing a project assignment, other than help from the instructional staff a project must be solely and entirely your own work. Working with another student or individual, or using anyone else's work in any way except as noted in this paragraph, is a violation of the Academic Integrity Policy. You may not discuss the design of any part of a project with anyone except the instructor or teaching assistants. Examples of questions you may not ask others might be "How did you implement this part of the project?" or "Please look at my code and help me find my stupid syntax error!". You may not use any disallowed source of information in creating either their project design or code. When writing projects you are free to use ideas or short fragments of code from published textbooks or publicly available information, but the specific source must be cited in a comment in the relevant section of the program. You may not use a generative AI system (e.g., Copilot, ChatGPT, or others) in completing your assignments.

Violations of the Code of Academic Integrity may include, but are not limited to:

  1. Failing to do all or any of the work on a project by yourself, other than assistance from the instructional staff
  2. Using any ideas or any part of another person's project, or copying any other individual's work in any way
  3. Using an AI system (such as Copilot or ChatGPT) to generate code that you submit as your own
  4. Giving any parts or ideas from your project, including test data, to another student
  5. Allowing any other students access to your program on any computer system
  6. Transferring any part of a project to or from another student or individual by any means, electronic or otherwise
  7. Posting project solutions online, even after the course has ended

If you have any question about a particular situation or source then consult with the instructor in advance. Should you have difficulty with a programming assignment you should see the instructional staff in office hours. Do not solicit help from anyone else in violation of these rules.

Right to Change Information

Although every effort has been made to be complete and accurate, unforeseen circumstances arising during the semester could require the adjustment of any material given here. Consequently, given due notice to students, the instructor reserves the right to change any information on this syllabus or in other course materials.


Other Resources